U.S. Pat. No. 4,541,766 dated Sep. 17, 1985, inventor Dahl, entitled "Device for Handling Packs of Elongated Articles, Especially Lumber Packs" describes a transfer device for transferring loads such as lumber packs into cells of multiple cell racks; the cells being provided with an anchor bar at their cell openings. The device of this patent consists of a jig or elongated frame which tine receivers fixed underneath the same to be supported by a forklift transversely of the same. Long arms are telescopically carried by the frame and have hooks at their ends to engage the anchor bars. The patent states that the transverse rollers supporting the load can be motorized to transfer the load from the jig to the rack cell.
It is obvious that the forklift must travel along the rack with the jig and load at a certain distance from the rack in order to prevent accidental collision of the load with the rack. It is therefore necessary that the telescopic arms can be extended a certain distance to hook onto the anchor bar at the rack opening. The arms must be extended and retracted by hand; this is an awkward and often dangerous operation especially when an operator must stand on a high platform to load the top cells of a rack several stories high.
Also since the arms are extended during the transfer of the load from the forklift to the rack, even if the main frame rollers are motorized, it is clear that the transfer roller closest to the rack cannot push the load entirely within the rack and therefore the load will protrude a certain extent at the front of the rack if the load is not manually further pushed into the rack and the protruding load will obstruct the transfer of additional loads into the rack.